feat(agent-office): 모바일 반응형 세로 스택 + 작업 시간 표기 개선

- 768px 이하에서 대시보드 세로 스택 + 에이전트 카드 아코디언 토글
- waiting/알림 있을 때 자동 펼침 및 좌측 강조 바
- 픽셀 오피스 캔버스 모바일 높이 140px로 축소 후 상단 배치
- 최근 작업 시간: completed_at 우선 + 오늘/어제/MM-DD HH:MM 포맷

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/pages/agent-office/components/AgentColumn.jsx

@@ -35,9 +35,12 @@ const AgentColumn = ({ agentId, meta, agentState, notification, onCommand, onApp
   const [input, setInput] = useState('');
   const [activeCommand, setActiveCommand] = useState(null);
   const [tokenUsage, setTokenUsage] = useState(null);
+  const [expanded, setExpanded] = useState(false);
 
   const state = agentState || { state: 'offline' };
   const commands = AGENT_COMMANDS[agentId] || [];
+  const needsAttention = state.state === 'waiting' || notification > 0;
+  const isOpen = expanded || needsAttention;
 
   useEffect(() => {
     getAgentTasks(agentId, 10)
@@ -89,11 +92,31 @@ const AgentColumn = ({ agentId, meta, agentState, notification, onCommand, onApp
     setActiveCommand(null);
   };
 
-  const formatTime = (t) => t ? t.replace('T', ' ').slice(11, 19) : '';
+  const formatTaskTime = (task) => {
+    const iso = task.completed_at || task.created_at;
+    if (!iso) return '';
+    const d = new Date(iso);
+    if (isNaN(d.getTime())) return '';
+    const now = new Date();
+    const pad = (n) => String(n).padStart(2, '0');
+    const hm = `${pad(d.getHours())}:${pad(d.getMinutes())}`;
+    const sameDay = d.toDateString() === now.toDateString();
+    const yesterday = new Date(now); yesterday.setDate(now.getDate() - 1);
+    const isYesterday = d.toDateString() === yesterday.toDateString();
+    if (sameDay) return `오늘 ${hm}`;
+    if (isYesterday) return `어제 ${hm}`;
+    return `${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${hm}`;
+  };
+
+  const handleHeaderClick = (e) => {
+    e.stopPropagation();
+    setExpanded(v => !v);
+    onClearNotification();
+  };
 
   return (
-    <div className="ao-col" onClick={onClearNotification}>
-      <div className="ao-col-header" style={{ borderColor: meta.color }}>
+    <div className={`ao-col ${isOpen ? 'ao-col--open' : 'ao-col--collapsed'} ${needsAttention ? 'ao-col--attention' : ''}`} onClick={onClearNotification}>
+      <div className="ao-col-header" style={{ borderColor: meta.color }} onClick={handleHeaderClick}>
         <span className="ao-col-name" style={{ color: meta.color }}>{meta.name}</span>
         {tokenUsage && tokenUsage.total_tokens > 0 && (
           <span
@@ -105,8 +128,12 @@ const AgentColumn = ({ agentId, meta, agentState, notification, onCommand, onApp
         )}
         <span className={`ao-col-state ao-col-state--${state.state}`}>{state.state}</span>
         {notification > 0 && <span className="ao-col-badge">{notification}</span>}
+        <span className="ao-col-chevron" aria-hidden="true">{isOpen ? '▾' : '▸'}</span>
       </div>
 
+      <div className="ao-col-body">
+
+
       {state.detail && (
         <div className="ao-col-detail">{state.detail}</div>
       )}
@@ -153,7 +180,7 @@ const AgentColumn = ({ agentId, meta, agentState, notification, onCommand, onApp
                 <span className="ao-col-task-badge" style={{ background: badge.bg }}>{badge.label}</span>
               </div>
               <div className="ao-col-task-time">
-                {formatTime(task.created_at)}
+                {formatTaskTime(task)}
                 {task.result_data?.telegram_sent !== undefined && (
                   <span className="ao-doc-tg-status">{task.result_data.telegram_sent ? ' TG OK' : ' TG Fail'}</span>
                 )}
@@ -168,6 +195,7 @@ const AgentColumn = ({ agentId, meta, agentState, notification, onCommand, onApp
           );
         })}
       </div>
+      </div>
     </div>
   );
 };